The pistons of gasoline engines, diesel engines, and high performance engines become easily overheated during operation. Pressure actuated oil jets have long been used to cool the under side of the pistons in such reciprocating engines. Such oil jets are often mounted in a bore on the underside of the engine block and receive oil under pressure from an oil gallery. These oil jets also incorporate a check valve to supply oil to the oil jet when a predetermined oil pressure is achieved and also prevent siphoning off of needed oil pressure during low oil pressure conditions.
Oil jets spray oil into cooling channels on the underside of the pistons, cooling the piston crowns and surrounding cylinder wall by absorbing heat (thus lowering combustion chamber temperatures). This occurs while the engine is running. This practice reduces piston temperatures, which helps the engine develop more power and assists in lubricating the piston and cylinder wall to increase durability. The extra oil layer on the cylinder bores and reciprocating components also minimizes noise that typically emanates from these components. The optimum operating temperatures also enhance the life of the critical engine parts and reduce maintenance costs.
There are two standard types of pressure actuated oil jets used in the industry, each comprising a two-part configuration. As shown in FIG. 1, typical pressure actuated oil jets comprise a two-piece construction comprising an oil jet body 10 and an oil jet valve 12. The oil jet body 10 comprises a main body 14 having a valve aperture 16 at one end and a bolt-receiving aperture 18 at the other end. Extending from the sides of the main body 14 are two nozzles 20 which are in fluid communication with the interior of the valve aperture 16.
The valve 12 generally comprises a tubular sleeve 22 having a threaded exterior portion 24 and a pair of oil exiting apertures 26. The sleeve 22 is further connected to an oversized head 28 at one end. Therefore, in assembly of the typical two-piece oil jet assembly, the valve 12 is inserted within the valve aperture 16 until the oil exiting apertures 26 of the valve 12 line up with the nozzles 20. The threaded portion 24 of the valve 12 threadedly engages a threaded bore in the lower portion of the engine block which transfers oil under pressure from the oil gallery to the valve 12.
There are generally two valve constructions used in the industry to handle pressure actuation: a ball valve construction (shown in FIG. 1A) and a piston valve construction (shown in FIG. 1B). While both constructions are further described below, it should be understood that for simplicity, like elements are identified by like numbers.
As best shown in FIG. 2, the ball valve 30 comprises a tubular sleeve 32 connected at one end to an oversized head 40. The sleeve further includes a pair of oil exiting apertures 36 which communicate with the nozzles of the oil jet body when the ball valve is placed within the valve body 10. A bore 38 extends through the head 40 and sleeve 32 as a passage for oil entering the ball valve 30. At the end opposite the head 40, the bore 38 tapers to create a seat 42 which communicates with an oil entrance opening 44.
A spring 46 is held within the bore 38 and urges a ball 48 against the seat 42 to create a valve-closed position. A cap 50 is placed over the bore 38 at the head 40 to retain the spring 46 within the sleeve 32. When the oil pressure is above a predetermined value, oil under pressure passes through the oil entrance opening 44 to overcome the spring force and depress the ball 48 against the spring 46 thereby creating a valve open position. The oil under pressure enters the bore 38 and exits the oil exiting openings 36 as indicated by the arrows X and Y of FIG. 2. The oil exiting apertures 36 are in fluid communication with the nozzles in the separate body 10 which direct oil to the pistons. When the oil pressure falls below a predetermined value, the spring 46 urges the ball 48 against the seat 42 to prevent a siphoning off of oil pressure and create a valve-closed position.
A particular disadvantage with the ball valve construction is that the ball 48 is unstable and is capable of lateral movement within the bore 38 as shown by arrows A and B. The unstable ball 48 begins to vacillate in response to the high-pressure oil flowing therearound. Such vacillation agitates the oil causing aeration which decreases the cooling and lubricating effect of the oil.
As shown in FIG. 3, the second oil jet configuration comprises a piston valve construction. The piston valve 52 comprises a tubular sleeve 32 connected at one end to an oversized head 40. The sleeve further includes a pair of oil exiting apertures 36 at its lower end which communicate with the nozzles of the separate oil jet body 10. A bore 38 extends through the head 40 and sleeve 32 as a passage for oil entering the piston valve 52. At the end opposite the head 40 and below the oil exiting apertures 36, the bore 38 tapers to create a seat 42 which communicates with an oil entrance opening 44.
A spring 46 is held within the bore 38 and urges a piston 54 against the seat 42 to create a valve-closed position. A cap 50 is placed over the bore 38 at the head 40 to retain the spring 46 within the sleeve 32. When the oil pressure is above a predetermined value, oil under pressure passes through the oil entrance opening 44 to overcome the spring force and depress the piston 54 and reveal the oil exiting apertures 36 thereby creating a valve open position. The oil under pressure enters the bore 38 and exits the oil exiting openings 36 as indicated by the arrows Y and X of FIG. 3. The oil exiting openings 36 are in fluid communication with the nozzles in the separate body 10 which direct oil to the pistons. When the oil pressure falls below a predetermined value, the spring 46 urges the piston 54 against the seat 42 to prevent a siphoning off of oil pressure and create a valve-closed position.
The piston valve design generally reduces the agitation and aeration because the piston head 54 is guided by the cylinder wall with no unstable object in the oil flow path. While the piston valve design has advantages over the ball valve design, both designs are generally made from an excessive number of parts which are expensive to manufacture and difficult to assemble.
Therefore, there is a need in the art to create a fluid jet that is easier to manufacture and has fewer component parts.
There is also a need in the art to create a fluid jet that is more cost effective to manufacture and less labor intensive to produce.
There is also a need in the art to provide a fluid jet that reduces the turbulence and aeration of the fluid during flow through the oil jet.